Science award winners show their stuff to high schoolers

Louis E. Brus studied the behavior of quantum dots,nanocrystals that behave like large bulk crystals. Quantum dots are semiconductors with electrons that can be controlled very precisely. As partof the science festival, at Franklin Institute, kids will see realsamples of nanocrystals that emit light in a rainbow of colors and playwith a macro-scale model that demonstrates how the different sizes ofnanocrystals create each color.Tuesday April 24, 2012. ( DAVID SWANSON / Staff Photographer )

By Tom Avril, INQUIRER STAFF WRITER

Posted: April 25, 2012

The week is crammed with carefully orchestrated events for the 2012 winners of the Franklin Institute awards in science and engineering, including academic lectures, luncheons and a black-tie dinner.

Tuesday morning, however, was time for some scientific uncertainty: exposure to high school students.

Five of the nine award recipients stood gamely behind exhibit tables for 90 minutes, fielding questions from a crowd of teenaged visitors to the museum. The scientists patiently explained their work over and over again as new groups of students pressed in close, scrutinizing exhibits on such topics as climate change, black holes and artificial intelligence. Interacting with the public has long been a part of the experience for the winners of the prestigious awards, which were first bestowed in 1824 and have gone to such luminaries as Marie Curie and Albert Einstein.

Louis E. Brus, a pioneer in the field of quantum dots, was worried afterward that he had not sufficiently connected them for his young charges.

“It was hard to explain to the high school kids,” said Brus, a professor of chemistry at Columbia University.

He needn’t have been concerned, if the reaction of Phillip Azzari was any guide. Azzari, a junior at Haddon Heights High School, spent a good 10 minutes soaking up Brus’s descriptions of the high-tech dots, also called nanocrystals.

“It’s pretty brilliant,” Azzari said of Brus’s work.

On the table in front of Brus stood three small cylinders that glowed with an eerie light. They were filled with solutions of different-sized nanocrystals made from a material called cadmium selenide. The selling point for these tiny particles is that when bathed in light, they emit light of their own — a property that has potential for such applications as energy-efficient flat-panel televisions and medical imaging equipment.

In this case, the cylinders were placed under a beam of ultraviolet light, causing the particles inside them to shine pink, red and yellowish green. The color that such particles emit depends on their size. Smaller ones emit light toward the blue-violet end of the visible spectrum, larger ones toward the red end. (Relatively larger, that is. All quantum dots have diameters in the range of a few nanometers — billionths of a meter.)

Brus discovered the properties of these crystals three decades ago while working at the famed Bell Labs in New Jersey, in an attempt to devise better transistors, but the particles are now starting to yield a wide range of applications that the scientist never envisioned. In addition to flat-panel screens, currently in development in Japan, other potential uses include solar panels and high-effiency light bulbs — a clear illustration of the value of basic research, he said.

“People invent things, and they have some idea what they might be useful for,” Brus said after speaking with students. “They’re typically wrong. But the result is published, and the open literature is read all over the world by everybody.”

Near Brus’s table stood Rashid Sunyaev, who won the Franklin Instistute medal in physics. He and Franklin Institute astronomer Derrick Pitts demonstrated the theory behind black holes, using a stretchy piece of black fabric. A few feet away was the husband-and-wife team of Lonnie G. Thompson and Ellen Mosley-Thompson of Ohio State University, who were recognized for their study of ice cores and global warming. Vladimir Vapnik, who works at NEC Labs in Princeton, N.J. and won his award in computer and cognitive science, explained how computers can accomplish certain tasks that are second nature for the human brain, such as recognizing faces.

The award winners were announced in December. Some of the recipients were unable to attend the event for high-schoolers Tuesday morning, but all nine are scheduled to be present Thursday night when the awards are presented.

Azzari, the Haddon Heights junior, was plenty satisfied with his brief exposure to some big-name scientists. He is taking an advanced-placement biology class this year, followed by advanced-placement chemistry and physics next year, and after his meeting with Louis Brus, he said he was even more determined to consider a career in the sciences.

For the winners of the Franklin Institute awards, a key part of their mission was accomplished.